Stereoscopic video image display appliance wearable on head like spectacles

ABSTRACT

Object of invention is such an appliance which is suitable for stereoscopic displaying of video images. It is wearable on head having a common stiff frame with two video image displays built in it; then an optical system, containing lenses and mirrors or prisms, is located, arranged symmetrically. Video image diplays (1), e.g. cathode ray tubes, while wearing on head, are located near the temples; in front of the screen (3) there is a mirror or a prism having reflecting surface, having of 45°-75° angles with the plain of the screen on two sides symetrically fitting into optical train between the screen (3) and the concerned pupil, then a lense or lense-system (8), then there is a reflecting mirror (7) having the area not greater than that of the average pupil, in front of the pupils (5), fixing of this mirror (7) is made of transparent material or is covered. The enumerated elements are built in the frame cover having many parts, from which part left and right side cover (9) contain video image display (1), mirrors or prisms (4) in front of the screen (3) and lenses or lense-systems (8), its connecting element (12) is transparent material and/or is constructed out of the virtual sight and rests on the ridge of the nose.

TECHNICAL FIELD

The invention relates to an appliance serving for stereoscopic imagedisplay which can be worn on head and it has two video displays mountedin a common stiff frame and there is an optical system consisting oflenses and mirrors arranged symmetrically on the right and left sides ofthe head in such an order that it ensures simultaneous watching of boththe surroundings and tv image practically without disturbing each other.

BACKGROUND ART

It is a general endeavour in case of most people to spend time oftravelling and waiting in a more useful way, getting informed orentertaining. Its traditional means besides newspapers and books are thewide-spread walkman (cassette player with stereo earphones) and theradio walkman (earphones with radio receiver).

In spite of the fact that most popular amusement in the homes precedingreading and listening to radio is watching tv and video, however it hasnot spread in public vehicles, in streets, etc. Its most importantreasons are: screen size of miniaturized tv is too small to enjoy theimage: watching small picture for a long time strains the eyes;increasing the picture is limited because of claim of portability,ability to keep it in a pocket, on the other hand the limit that screenheld in hands can be maximum in an arm's length. Consequently weincrease size of picture in vain; over a certain limit picture seen froma too close distance shows line-structure; screen of tv set held inhands, because of sight, is watched by people standing around, which canbe disturbing; at day-light or at strong inner lighting image fades orgets contrastless.

Such an appliance is suitable for solving the problem which: 1) light,2) small sized, 3) picture appears in a good distance (i.e. 2-3 meters),4) picture cannot be seen by others, 5) the appliance need not be heldin hands, 6) while watching it, the person can see his surroundingsfree, 7) screen is strongly shaded from outer light, in this way it isperfectly contrasty.

The U.S. Pat. No. 4,310,849 is known (Jan. 12, 1982, Stuart M. Glass,"Stereoscopic video system") which is a stereo image and voicebroadcasting unit fixed to the head, where tv pictures of right and lefttype is forwarded to the left and right eyes by fibreglass optics,voices forwarded to ears by stereo earphones. The appliance can be fixedto the head by head band system. Its disadvantages are: band system isheavy and big, wearing it is uncomfortable and striking, and the band infront of the eyes disturbs looking around, i.e. its wearer can see onlytv screen and not the surroundings. Tv mounted into helmet is describedin G. V. Mamchev's book "The Stereo Television" (Muszaki Konyvkiado,Budapest - Mir Publishing House, Moscow, 1981, page 58). A special coveris fixed to the forehead part of the viewer's helmet in which twocathode ray tubes are situated almost vertically with looking downwardsabove the left and right eyes, and viewer sees the two screens through alense and a mirror. The helmet is heavy and big in this case too, andthe cover including the mirrors disables the viewer to see thesurroundings free.

The U.S. Pat. No. 4,559,555 has the same operation principle (Dec. 17,1985, Arnold Schoolman, "Stereoscopic viewing system"), a tv set mountedin a helmet as as described by its FIG. 5-7, arrangement of elements andits disadvantages are similar.

The U.S. Pat. No. 4,706,117 (Nov. 10, 1987, Arnold Schoolman, "StereoLaser disc viewing system") describes a tv set of various constructionfixed to the head. According to its FIG. 6-8 there is a protrudingextension is a big closed unit in front of the viewer's eyes, in whichthere are two built-in objectives, two screens with liquid crystal andtwo lamps for lighting the screen and the extension is fixed to the headby a head band system. According to appliance described in its FIG. 10there are two lenses in front of the eyes and beyond them there are twoLCD screens. In the cases of appliance mentioned in above patentdescription, the protruding extension makes possible only watching tvand it totally closes the surroundings and their fixing system are bigand uncomfortable.

FRG Patent No. DE 3534162 A1 (Nov. 13, 1986, Wolfgang Andrich,"Tragbarer videomonitor") describes such a non-stereoscopic tv setmounted into a helmet, in which case there is a tv image display on topof viewer's head, its image is projected in the eye by a first lense, amirror, a second lense and a transparent mirror. Its disadvantage is thebig sized helmet and the fact that semi-transparent mirror is anambiguous solution, as it does not make possible to see either thesurroundings or tv image undisturbed way, because both can be seen onthe same location projected on each other.

At last mention U.S. Pat. No. 4,636,866 (Dec. 22, 1983, Noburu Hattori,"Personal Liquid Crystal Image Display") which describes a protrudingextension constructed as close unit which can be fixed to the head by ahelmet. There are one or two LCD screens in the protruding extensionseen by viewer through a lense or lenses and mirrors. Disadvantages ofthe appliance are similar to the previous ones.

To summarize all these, common characteristic feature of known solutionsrealising tv image display wearable on the head are the relatively bigsize and weight that makes its wearing on the one hand uncomfortable andtiring, on the other hand wearing such helmets in the streets, in publicvehicles, etc. is striking. Possibilities of using them are furtherlimited by the fact that user of this appliance has limited ability toorientate, that is why this appliance can be used for watching tv onlyunder undisturbed circumstances.

DISCLOSURE OF THE INVENTION

The aim of our invention is to eliminate above shortcomings to ensurenew usage circle. Our invention is based on the recognition that freeoutlook on the surroundings--beside enjoying perfect image fading intothe surroundings in a pleasant way--can be ensured by a small sized,pleasant for wearing, esthetic appliance in case we combine suitableoptical and electronical principles during designing the appliance.

General solution of the task is such an appliance which has imagedisplays, e.g. cathode ray tubes, located while wearing it on the headin front of the temples; in front of the screens and fitting into theoptical train between the screen and the appropriate pupil as well as onthe two sides simmetrically there is a mirror or prism with reflectingsurface each, having 45°-75° angles with the plain of the screen, then alense or lense system each, then in the axis of the eyes, in front ofthe pupils there is a mirror each fixed, essentially, without anyoptical shading elements, having a reflecting surface of maximum doubleof the iris's average area, which fits into optical train according tothe outlines of the screen and the enumerated elements are built in sucha frame-cover consisting of several parts, and from which the left andright cover contain the image displays, e.g. cathode ray tubes, mirrorsor prisms and lenses or lense systems being in front of the screen, andits joining element allows free outlook, being advantageouslytransparent or being beyond the visual field and rests on the ridge ofthe nose.

BRIEF DESCRIPTION OF DRAWINGS

We describe our invention in details with the help of embodymentexamples. Figures used for description show the following:

FIG. 1: Sketchy arrangement of elements of the appliance according tothe invention in top view in case of cathode ray tubes.

FIG. 2: Appliance according to the invention, perspektively in case ofcathode ray tubes.

FIG. 3: Sectional drawing of a part of the appliance according to FIG.2.

FIG. 4: Sketchy arrangement of elements of appliance according toinvention in top view in case of LCD screens.

FIG. 5: Uncovering relation of mirrors being in front of the eyes invertical plain.

MODE OF CARRYING OUT THE INVENTION

According to FIG. 1 video image displays (1) are situated along left andright temples of the person's head (2) with screens (3) looking forward.Because of symmetrical relations in the future we describe onlyarrangement of the left side. In front of the screen (3) an opticalelement with reflecting surface, i.e. a mirror or a prism is situated.In front of the pupil (5) of the left eye, we have described only itstop view place because of uncovering of eyebrows (6), the mirror (7) issituated in 1-3 cm's distance, which is a metal mirror so as to avoiddouble reflecting. Its shape advantageously is a lying rectanglesuitably to screen (3) to be reflected, even more punctually it is sucha trapezium whose longer side of the parallel ones is farther from thepupil (5). It is placed a bit to the right from the axis of the eye infront of the pupil (5). The lense or lense system (8) is situatedbetween the mirror or prism (4) and the mirror (7), with optical axisapproximately coinsiding with quadrat connecting centre of reflectingsurfaces, their focus is longer than length of the quadrant deflectingaccording to optical train which connects optical main point withcentral point of screen (3). The video image display (1), the mirror orprism (4) and the lense or lense system (8) are built in the cover (9),whose end is open at the lense or lense system (8). The fixing element(11) is joined to the end of the cover (9) at the ear, its shape isadvantageously is turning downwards similarly to the traditionalspectacle-temple.

Regarding both sides of FIG. 1, joining element (12) stiffly connectsleft and right covers (9) which is made of transparent material orbecause of its stereoscopic construction it does not disturb outlook.Mirrors (7) are stiffly fixed to the joining elements (12). The middleof the joining element (12) is advantageously constructed like an archlying on the ridge of the nose (13). Display driving circuit can also beplaced beside the video image display (1) in the cover (9). The electriccables (20) lead through the opening of the cover (9) lead to the unitserving as the source of image and voice signals as well as feedingvoltage which can be a tv-tuner, image recorder-player appliance,computer, video camera, etc. Earphones (14) can be placed outside of thecover (9) or can be built in the lengthened over (9); in special cases,as e.g. connecting to computer, earphones (14) can be omitted.

FIG. 2 shows one way of construction of the joining element (12). Bothends of cylinder shaped body made of thin transparent plate,advantageously of plastic, are fixed to the covers (9), e.g. glued.Fixing mirrors (7) to the joining element (12) can be done either withdistortion free transparent elements (e.g. glass or plastic plates),either with elements being behind and covered by the mirror (7).

Embodyment of the latter is shown in FIG. 3. Ball joint or journal joint(11) is fixed to the backside of the mirror (7), advantageously glued,and trained end of inner component pierce through vertical opening (17)of the joining element (12). The joining element (12) is surrounded byscrew-nuts. In this way fine setting of the mirror (7) in all directionsis possible. Lense or lense-system (8) is supplied with setting elementwhich can be e.g. tube with screw-thread (19).

In FIG. 4 video image display (1) is an LCD appliance built in the cover(9), as per arrangement is shown, behind it a light diffusor i.e. asemi-transparent plate e.g. a mat pane, spreading light homogenously, issituated. Cover (9) is divided into two parts which are turnablyconnected with a joint (22), in this way two temples of the appliance,similarly to spectacles, can be folded. Open ends of previous coveringparts are closed serviceable with light diffusors (21) and (23), e.g.mat panes as covering plates. Light-source of white colour is built inbehind the light diffusor (23) which has switchable electric connectionwith an electric source (25) built in the cover (9). The cover (9) endsin the fixing element (11) whose shape is preferably curving downwards.

Characterized according to its operation, the beam starting from thescreen (3) reflecting on the mirror or prism (4), focused by the lenseor lense-system (8) and at last reflecting on the mirror (7) gets in theeye through the pupil. After all the viewer person looks with both eyesin the direction of the mirror (7), behind it, at the location of thevirtual image (26), which is the enlarged image of the screen (3) andseems in bigger distance than that is. That is why the two images in thecase of both equal images and stereo image pairs/images, recorded fromleft and right visual angle/ it becomes a single image. In the case ofstereo image pair this picture has the virtual view of three dimensions.

Preferably we choose the size of the screen (3) and enlarginglense-system (8) so that angle β should be approximately between 10° and15°, this equals with the angle of watching tv from 2-3 m. In case wemove lense or lense-system farther along its optical axis from themirror or prism (4) and at the same time from the screen (3), size anddistance of virtual image (26) increases at the same angle β. In orderto make distance and size of the picture the most comfortable, we supplysetting element to the lense or lense-system (8) which can operateseparately or together. Size and location of mirrors (7) are exactlyproper for both eyes to see just the screen (3) and only the screen. Inother words the mirrors (7) cause only minimum shading for the personwatching the outer surroundings. The person sees the virtual image (26)by itself, without any dark frame put on image of the current outerenvironment, in other words tv image starts to float in front ofbackground of the surroundings. As it is seen from the above to makevirtual tv images, seen by left or right eye, covered it requiresprecise setting of mirrors (7) one according to the person's eyes.Setting can be done by turning or paralelly slipping the mirrors (7).

FIG. 5 explains or shows that mirrors (7) practically do not or hardlydisable the person to watch the surroundings free from superimposedimages. As mirrors (7) are not transparent, while watching visual image(26), the objects surroundings behind them are covered. However if e.g.viewer looks at a much remote point (27), he sees it also with botheyes, though this point should be uncovered behind the visual image(26). Explanation of the phenomenon is that fact that pupils of eyes,looking far, move away from each other because of little correcting turnof the eyeballs, in this way pupils in situation (28) can see betterbehind the mirror (7). After all, only the lined field (33) surroundedby half lines (29) and (30), as well as by (31) and (32) (starting frompupils in situation (28) and touching edges of mirrors (7) remainuncovered for both eyes. The thesis is widely true according to whichwhile watching visual image (26) with T territory (uncovering thesurroundings) watching any other point being closer or farther,uncovering for both eyes in smaller than T. At last as pupil is notpunctiform, it has extension, at above phenomena contours become blurredwhich increases validity of previous thesis.

As a summery, our invention is a spectacle shaped video image displaywhich makes possible not only undisturbed watching of tv image but alsoof the outer surroundings or with smaller uncovering that previous tvimage.

From the described embodyments we can see that depending on the sort ofimage display appliance can be constructed in various ways. In the caseof image display with liquid crystal electronic driving display withliquid crystal can be built in the cover (9) according to FIG. 4, eventv tuner too, in latter case it is complete tv receiver--with theaddition of areal and earphones. In case of coloured image display inone basic colour (e.g. blue) on one screen and in the mixture of theother two basic colours (red and green) on the other screen, then inviewer's mind colours mix in a binocular way and the stereoscopic imageseems to be coloured.

We claim:
 1. A video image display appliance for wearing on a head, thehead having an eye for receiving light from a field of vision, saidappliance comprising:a frame having a first portion disposed adjacentthe eye, said first portion defining a transparent section through whichlight from the field of vision passes and enters the eye, and a secondportion connected to said first portion adjacent the eye; a video imagedisplay mounted on said second portion and projecting an image along anoptical train; and an opaque reflective means connected to said firstportion and disposed on said optical train for receiving and reflectingsaid image toward the eye, said opaque reflective means being disposed 1to 3 centimeters from the eye, said opaque reflective means beingdisposed to block a portion of the light from the field of vision.
 2. Avideo image display appliance for wearing on a head, said head having aneye for receiving light from a field of vision, the eye having a primaryline of sight, said appliance comprising:a frame having a first portiondisposed adjacent the eye, said first portion defining a transparentsection through which light from the field of vision passes and entersthe eye, and a second portion connected to said first portion adjacentthe eye; a video image display mounted on said second portion andprojecting an image along an optical train; and an opaque reflectivemeans connected to said first portion and disposed on said optical trainfor receiving and reflecting said image toward the eye, said opaquereflective means being disposed below or intersecting said primary lineof sight to block a portion of the light from the field of vision.
 3. Avideo image display appliance of claims 1 or 2 further comprising afirst reflective surface disposed on said frame between said video imagedisplay and said opaque reflective means for receiving said imageprojected by said video image display and reflecting said image alongsaid optical train.
 4. A video image display appliance of claim 3further comprising a focusing means disposed between said firstreflective surface and said opaque reflective means for receiving saidimage reflected by said first reflective surface and focusing said imageat a predetermined focal length on said opaque reflective means.
 5. Avideo image display appliance of claim 4 wherein said focusing meanscomprises a lens mounted on said frame.
 6. A video image displayappliance of claim 5 wherein said lens is movable mounted by a lensmounting means such that said lens is reciprocally adjustable in adirection of an optical axis of said lens.
 7. A video image displayappliance of claim 6 wherein said lens mounting means comprises a tubehaving a screw thread within which is mounted said lens.
 8. A videoimage display appliance of claim 4 further comprising:said first portionof said frame defining a second transparent section disposed in from ofa second eye, said frame having a third portion connected to said firstportion adjacent the second eye; a second video image display disposedon said third portion and projecting a second image along a secondoptical train; a second opaque reflective means connected to said firstportion and disposed on said optical train for receiving and reflectingsaid image into the second eye, said second opaque reflective meansbeing disposed to block a portion of a field of view of the second eye;a third reflective surface disposed on said frame between said secondvideo image display and said second opaque reflective means forreceiving said second image projected by said second video image displayand reflecting said image along said second optical train; and a secondfocusing means disposed between said third reflective surface and saidsecond opaque reflective means for receiving said second image reflectedby said third reflective surface and focusing said second image at saidpredetermined focal length on said second opaque reflective means
 9. Avideo image display appliance of claim 8 wherein said first image is oneor more first colors, and said second image is one or more secondcolors.
 10. A video image display appliance of claim 8 wherein saidfirst and second images are substantially the same.
 11. A video imagedisplay appliance of claim 8 wherein the combination of said first andsecond images viewed by said first and second eyes creates astereoscopic video image.
 12. A video image display appliance of claim 4wherein said opaque reflective means comprises a metal mirror surface.13. A video image display appliance of claim 4 wherein said video imagedisplay comprises a cathode ray tube.
 14. A video image displayappliance of claim 4 wherein said video image display comprises a liquidcrystal display and a light source, said light source being disposed toemit light through said liquid crystal display.
 15. A video imagedisplay appliance of claim 3 wherein said opaque reflective meanscomprises a metal mirror surface.
 16. A video image display appliance ofclaim 15 wherein said video image display comprises a cathode ray tube.17. A video image display appliance of claim 5 wherein said video imagedisplay comprises a liquid crystal display and a light source, saidlight source being disposed to emit light through said liquid crystaldisplay.
 18. A video image display appliance of claim 3 wherein saidvideo image display comprises a cathode ray tube.
 19. A video imagedisplay appliance of claim 3 wherein said video image display comprisesa liquid crystal display and a light source, said light source beingdisposed to emit light through said liquid crystal display.
 20. A videoimage display appliance of any one claims 1 or 2 wherein said videoimage display comprises a cathode ray tube.
 21. A video image displayappliance of any one of claims 1 or 2 wherein said video image displaycomprises a liquid crystal display and a light source, said light sourcebeing disposed to emit light through said liquid crystal display.
 22. Avideo image display appliance of claim 21 wherein said second portion ofsaid frame is foldably connected to said first portion of said frame bymeans of a joint.
 23. A video image display appliance of any one ofclaims 1 or 2 further comprising a display driving circuit electricallyconnected to said image display.
 24. A video image display appliance ofclaim 23 wherein said display driving circuit comprises a televisiontuner.
 25. A video image display appliance of claim 23 wherein saiddisplay driving circuit comprises a video recorder/player.
 26. A videoimage display appliance of claim 23 wherein said display driving circuitcomprises a computer.
 27. A video image display appliance of claim 23wherein said display driving circuit comprises a video camera.
 28. Avideo image display appliance according to claim 1 wherein the eye has aprimary line of sight, and said opaque reflective means being disposedbelow or intersecting said primary line of sight.
 29. A video imagedisplay appliance according to claims 1 or 2 further comprising at leastone earphone disposed on said second or third portions of said frame.30. A video image display appliance according to claim 2 wherein saidopaque reflective means is disposed 1 to 3 cm from the eye.